1. Field of the Invention
The present invention relates to a camera with a built-in electronic flash or strobe which effects flash exposure control even during the daytime.
2. Description of Related Art
Outdoors, it often happens in taking portraits that back-light and the direct sun right above over the subject create harsh shadows on the subject, in particular, on the subject's face. In order to prevent harsh shadows on the subject in such a backlit situation, it is helpful to utilize what is called an ever-flash exposure technique in which a built-in electronic flash is fired for every exposure even during the daytime. Because of extensive latitude of exposure, the ever-flash exposure is beneficially used with negative color films. However, if flash illumination is simply provided during flashmatic exposure in which the electronic flash is fired at apertures corresponding to subject distances to give proper exposures determined based on the intensity of ambient scene light or the brightness of scene, pictures display too enhanced contrast between a subject image and a background which gives a dull impression.
One such ever-flash exposure control camera is that described in Japanese Laid-Open Patent No. 56 - 149,022. The approach used is to control the amount of flash light directed to the subject according to scene brightness which is detected by a photo-electric sensor. For the purpose of providing a brief description about the prior art ever-flash exposure control that will enhance an understanding of the present invention, reference is made to FIG. 10.
As shown in FIG. 10, when there is no ambient scene light contributory to exposure, the ever-flash exposure control system energizes the electronic flash to provide flash illumination light which bears a proportion, namely a contribution ratio, of 100% relative to the quantity of light necessary to proper film exposure. With an increase in the quantity of ambient scene light until the proper film exposure is attributable 70% to the ambient scene light, the ever-flash exposure control system provides the quantity of flash illumination light forming the remaining portion of the quantity of light necessary for the proper film exposure which is changeable in exposure contribution ratio to 30% so as to give 100% of the quantity of light necessary for the proper film exposure. Together, when the quantity of ambient scene light further increases, the ever-flash exposure control system automatically regulates an aperture of the shutter so as to sustain only 70% of the quantity of ambient scene contributory to the proper film exposure. Accordingly, the exposure contribution ratio of the total quantity of ambient scene light and flash illumination light is always 100% of the quantity of light necessary for the proper film exposure over the entire range of potential scene brightness.
However, since the prior art ever-flash exposure control system provides the quantity of flash illumination light of at least 30% of the quantity of light necessary for proper film exposure even in a range of relatively high scene brightness, the brightness of an subject is enhanced, resulting in a decline of the quantitative ratio of light from the subject relative to light from the background. In such an event, there is provided a picture with a dull background which always spoils photographic pleasure. Further, since the prior art ever-flash exposure control system provides the quantity of flash illumination light forming a proportion of at least 30% of the quantity of light necessary for proper film exposure regardless of subject distances, in close up shots in which a subject fills most of the frame, the brightness of the subject is enhanced. In such case, there is provided a picture with an image of the subject standing out in bold relief against a dark background which always gives an odd feeling.